College of Material and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China.
Analytical & Testing Centre, Sichuan University, Chengdu 610064, China.
J Phys Chem Lett. 2021 Sep 30;12(38):9205-9212. doi: 10.1021/acs.jpclett.1c02809. Epub 2021 Sep 16.
Triplet exciton formation is essential for photosensitization-based photochemistry and photobiology. The heavy atom effect (HAE), in the form of either external or internal mode, is a basic mechanism for increasing the triplet exciton yield of photosensitizers. Herein, we report a new HAE mode by noncovalent cohosting of heavy atoms and photosensitizers in a double-stranded DNA (dsDNA) matrix. With dsDNA bearing several thymine (T) or cytosine (C) mismatches, heavy atoms (e.g., Hg or Ag) and dsDNA-staining dyes (photosensitizers) were spatially adjoined in close proximity, thus resulting in enhanced phosphorescence and O generation from the photosensitizers. The dsDNA-hosted HAE provides highly selective recognition for the heavy atoms, which is not applicable in either the external or the internal mode. Considering the simpleness and efficiency of the spatially adjoined HAE, as well as the functionality of DNA, the proposed HAE mode is appealing for various singlet oxygen- and phosphorescence-related applications.
三重态激子的形成对于基于光敏化的光化学和光生物学至关重要。重原子效应（HAE），无论是外部模式还是内部模式，都是增加光致剂三重态激子产率的基本机制。在此，我们报告了一种新的 HAE 模式，即将重原子和光致剂非共价共容纳在双链 DNA（dsDNA）基质中。带有几个胸腺嘧啶（T）或胞嘧啶（C）错配的 dsDNA 承载了重原子（例如汞或银）和 dsDNA 染色染料（光致剂），它们在近距离空间上毗邻，从而导致光致剂的磷光和 O 生成增强。dsDNA 承载的 HAE 为重金属原子提供了高度选择性的识别，这在外部或内部模式中均不适用。考虑到空间毗邻 HAE 的简单性和效率以及 DNA 的功能，所提出的 HAE 模式对于各种与单线态氧和磷光相关的应用具有吸引力。
